Condensation product of naphthenic acid halide and process of making it



Patented on; 27, 1942 PRODUCT or mrnrnamc AND PROCESS or MAKING CONDENSATION IAIQID HALIDE OFFICE Eugene Lieber, Staten Island, N. Y., animalto Standard Oil Develo poration of Delaware pment Com No Drawing. Original application October 29,

1938, Serial No.

Divided and this application December 27, 1940, Serial No. 371,994

9 Claims.

The present invention relates to the art of producing lubricants, and more specifically to lubricating oils of low pour point, by the addition of pour depressants or wax modifying agents to waxy oils, and also to such depressants or modifiers.

Wax modifying agents are made by condensation or polymerization of various materials, but

exhaustive studies have shown that a great many polymers or condensation agents do not have these valuable properties. Most modifying agents are preparedfrom waxy hydrocarbons or materials which have a wax-like structure attributable to a relatively long hydrocarbon chain. It has now been discovered that valuable depressants or modifiers can be prepared from cheaper sources of materials and specifically from naphthenic acids which occur naturally in certain crude oils, notably those obtained from the Gulf 7 Coast of the U. S., certain portions of California,

Rumania, Venezuela and elsewhere. 1

This new type of depressants, as stated above, is'produced from naphthenic acids. are separated from the crude oil or fractions wherein they occur by known methods and they may be purified to whatever degree appears to be desirable. Such processes, being no part of the processes for producing Such acids Polymerization may be continued for-some time after the acid evolution has practically ceased, but too long a heating is undesirable as solids are apt to be formed. If desired, polymerization may be effected by the aid of catalysts, particularly aluminum chloride or its equivalents among the group of Friedel-Crafts or active halide catalysts. The conditions of reaction are substantially the same as given above; a temperature of at least about 400 is required, but it is preferable not to conduct the heating aboveabout 500 F., in the presence of these active catalysts. The time of reaction is about the same as given above and the results are substantially the same.

After polymerization has been effected, the

product is preferablydiluted with kerosene or a similar solvent and the solution is washed with present invention, need not be described in detail. In. the present process, the naphthenic acids are first converted into acid halides, preferably chlorides, by treatment with phosphorus chloride or the equivalent halides of the metalloids, for example, thionyl chloride.' The reaction progresse smoothly at the temperature of boiling water and the acid halide forms a layer which may be readily decanted.

The naphthenyl halides are then polymerized or condensed to produce the wax modifiers. The reaction may. be eflected by thermal means alone at temperatures from about 400 to 750 F., care being taken to avoid carbonization by too high or too rapid heating or by heating which is not uniform. It is desirable to thoroughly stir the polymerization product during reaction, preferably bypassing a current of nitrogen or other inert gas through the reaction mixture so as not only tocause agitation, but likewise to remove hydrogen chloride vapors which are evolved during the reaction. The'heating is continued for several hours until the evolution of hydrogen chloride has practically ceased. The product thickens during the heating and it is desirable to conduct the reaction under a reflux condenser so asto permit the escape of the acid vapors. and

aqueous alcohol to remove the remainder of the acid. If catalyst is used, its hydrolysis is accomplished by the addition of the aqueous alcohol and the catalytic sludge separates from the solid layer so that it is readily removed in this way.

The kerosene or other solution is then distilled, preferably withfire and steam, up to about 500 or 600 -F., in order to remove the kerosene and the lower boiling fractions of the polymer.

The product recovered as a distillation residue is thick, viscous and gummy, usually of a dark green to brownish color, and is freely soluble in .mineral oils. It may be further purified by sulfuric acid treatment, but if it has been carefully prepared, it"is suitable for use as such. As a, pour point depressant, the material is added to the oil in proportion from about .1 to

ferent oils show different susceptibility to theaction of these depressants. As wax modifying agents, the materials are used in substantially the same amountsand are added to the waxy oil either before or after it is diluted with the to return liqtud materials for ..further reaction.'5 6

wax separating solvents. The actual separation of wax is made by sedimentation, centrifugation or filtration, and it is greatly assisted by the presence of these modifying agents.

' Example 1 Eighty-eight grams of, refined naphthenic acids from Columblan crude oil were converted to the naphthenyl chloride by heating with one molecular proportion of thionyl chloride. When evolution oi-sulfur dioxide and hydrogen chloride had ceased, the naphthenyl chloride was transferred to a suitable reactor fitted with a thermometer and outlet tube for HCl gas. grams of am. hydrous AlCla were added all at once and the mixture slowly heated to 450 F. and maintained thereat for 5 hours, at which'time the evolution of HCl had practically ceased. The mixture was cooled and taken up in 600 cc. of kerosene and washed with an alcohol-water mixture. After settling, the kerosene extract was distilled with fire and steam to 600 F. to remove low boiling material. A residue of 54 grams of a dark green viscous oil was obtained. This is a yield of 61 percent based on the naphthenic acids. The pour depressor potency was tested by blending in a waxy-oil. The following results were obtained:

Pour point, F. Original 011---..- +30 Original oi1+1% polymerized Co. napht. acids Original oil+5% polymerized Co. napht. acids -20 (better than) Example 2 The procedure and quantities of Example 1 were repeated exactly except that the polymerization was carried out in the absence of catalyst. Example 2 comprises two individual cases. In the first, the reaction was carried out at 400 F. for 5 hours, while in the second the reaction temperature was maintained at 480 F. for 5 hours. The recovery of the products was the same as described previously. The following table gives the results obtained: a

I Example 3 125 grams of naphthenic acids obtained from Venezuelan crude oil were converted to the naph- I thenyl chloride as described in Example 1. The

' resulting naphthenyl chloride was placed in a suitable reactorfitted with a return condenser, thermometer and inlet tube for inert gas (nitrogen) 15 grams of anhydrous A1013 were added as quickly as possible. A rapid stream of inert gas was passed through the mixture and the temperature raised to 450 F. and maintained thereat for 5 hours, at which time the evolution of HCl had practically ceased. After cooling the product was recovered as described in Example 1.. A yield of 67% based on the naphthenic acids was obtained. The pour depressor potency was obtained by blending in a waxy-oil. The following result was obtained:

. Pour point, F.

Original oil +30 Original oil+5% polymerized naph. acids 20 (better than) Example 4 This application is a division of co-pending application Serial No. 237,742, filed October 29, 1938, Patent No. 2,246,312.

'The present invention is not to be limited by any theory of the mechanism of the reaction nor to naphthenic acids of any particular source nor to any catalyst, but only to the following claims in which it is desired to claim all novelty inherent in the invention.

Iclaim:

1. A polymer obtained by condensation of naphthenic acid halide.

2. A polymer obtained by condensation of naphthenic acid chloride.

3. An improved process for preparing wax modifying agents comprising polymerization of naphthenic acid halides at temperatures within the range of 400 to 700 F.

4. An improved process for producing wax modifying agents comprising the condensation of naphthenic acid halides at temperatures between 400" and 700 F., during a prolonged period until evolution of acid vapors substantially ceases.

5. Process according to claim 4 in which the process is non-catalytic.

6. Process according to claim 4 in which 'the process is eflectedin the presence of a Friedel- Crafts catalyst at a temperature between about 400 and 500 F.

7. An improved process for producing wax volatile at temperatures up to about 500 F. under fire and steam distillation, and having wax-modifying properties, said product being derived by 'Friedel-Crafts auto-condensation of a naphthenic acid chloride.

EUGENE LIEBER.

A yield of only 32% based on 

